Light emitting diodes are useful for indoor and outdoor illumination, as well as other applications. Many such applications would benefit from an improved technology for managing light produced by a light emitting diode, such as forming an illumination distribution matched or tailored to application parameters.
For example, consider lighting a pathway having a thin, rectangular geometry. Conventional light emitting diodes could be mounted over the sidewalk, facing down, so that the optical axes of the individual light emitting diodes point towards the sidewalk. In this configuration, each conventional light emitting diode would cast a substantially circular illumination distribution poorly matched to the rectangular geometry of the pathway. A linear array of such light emitting diodes would undesirably cast a substantial amount of light outside the pathway or provide a splotchy pattern of uneven illumination on the pathway.
In view of the foregoing discussion of representative shortcomings in the art, need for improved light management is apparent. Need exists for a compact apparatus to manage light emitted by a light emitting diode. Need further exists for an economical apparatus to manage light emitted by a light emitting diode. Need further exists for a technology that can efficiently manage light emitted by a light emitting diode, resulting in energy conservation. Need further exists for an optical device that can transform light emanating from a light emitting diode into a desired distribution, for example creating a pattern that is long and narrow, elongate, linear in form, or ribbon shaped. Need exists for improved lighting, including for lighting pathways, walkways, aisles, emergency paths, and sidewalks, to mention a few representative examples. A capability addressing one or more such needs, or some other related deficiency in the art, would support cost effective deployment of light emitting diodes in lighting and other applications.